A polycarbonate resin obtained by reacting bisphenol A with a carbonate precursor has heretofore been widely used in many fields as an engineering plastic due to its excellent transparency, heat resistance, mechanical properties and dimensional stability. Due to the excellent transparency in particular, it is used in many applications as an optical material, and its use in such applications requiring heat resistance as light covers, gloves, electronic component materials, LED lenses, prisms, hard disk carriers, films for liquid crystal substrates of liquid crystal displays and retardation films has been considered in recent years. In the case of these applications, the ordinary polycarbonate resin obtained from bisphenol A has a problem. For instance, when it is used in the film for a liquid crystal display, it has a problem of insufficient heat resistance because a high temperature treatment of 180° C. or higher is required in an oriented film formation process, electrode formation process or the like. Further, when the conventional polycarbonate is used in the light cover or glove, it also has a problem in heat resistance due to an increase in heat quantity along with an increase in luminescence intensity of lights in recent years.
To improve the heat resistance of the polycarbonate, a method of using bisphenols having a structure which is bulky and is not easily movable is generally applied, and various polycarbonates have been proposed. Of these, polycarbonates having specific fluorene skeletons have been proposed (for example, JP-A 6-25401 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), JP-A 7-52271, JP-A 11-174424 and JP-A 11-306823). However, although these polycarbonates having fluorene skeletons are excellent in heat resistance, the initial color of articles molded from the polycarbonates has strong yellowness, so that an improvement in the color is required when they are used in optical applications or outer covering applications.
Further, since the polycarbonates having fluorene skeletons are liable to be degraded and yellowed very easily by irradiation of ultraviolet radiation after molded, applications thereof are limited when applied to optical components or outer covering parts.
Meanwhile, to prevent degradation or yellowing of the ordinary polycarbonate from bisphenol A by ultraviolet radiation, addition of benzotriazole or benzophenone based ultraviolet absorber to the resin (JP-A 11-35815) or addition of benzoxazine-one based ultraviolet absorber to the resin (JP-A 59-12952) has been proposed. Use of these ultraviolet absorbers has an effect of preventing degradation by ultraviolet radiation to some extent on articles molded from the ordinary polycarbonate from bisphenol A, depending on the type and amount of the absorber. However, since the above polycarbonate having a fluorene skeleton has a structure that is easily degraded by ultraviolet radiation in addition to having yellowness in the initial color after molding as described above, selection of the type and amount of an ultraviolet absorber is limited. For example, when an ultraviolet absorber is added to the polycarbonate having a fluorene skeleton in a sufficiently large amount to improve light resistance according to its type, a molded article therefrom may undergo detective moldings or coloration, or the heat resistance of the resin may deteriorate.